Manifold for engines



P 1947- c. G. BARRETT 2,427,115

MANIFOLD FOR ENGINES Filed Dec. 10, 1945 3mm m Charla sGIbarreR iiaifsssi a-z-i-s Q11,

limit the length or Patented Sept. 9, 1947 UNlTED STATES PATENT OFFICE roa enemas "Charles G. Barrett, Alexandria, Va.: Vera M. Baradministra rett ' trix of laidChar-les G. Barrett,

deeas'ed. asli'gnor to Edward 2. Magdeburger,

Washington, D. C.

I application December 10, 1045. Serial No. 633,910

ticularly to inlet manifolds for internal combustionengines'ofjthe compression ignition type having a plurality of. cylinders in line.

With such engines it is desirable to use individual inlet passages of conslderable length in order tofdeliver the maximum charge otair per cycle, and this is true whether a super-charger (such asa Bilchiturbocharger) is or is not used. vLlln either case, space considerations tend to the passages. The present invention affords a manifold not materially longer than theengine to which it is applied, and in which the. passages are oifadequate length and do notjdifferin'lengthto an obiectionable degree. The, desired result is attained by forming in the manifold shell, passages, one for eachcylinder,

each pas ge forming a substantially complete loop which is helically deformed. Consequently the passages nest neatly in a cylindrical shell and are so arranged that the connections from thefyarious' cylinders to' the shell and to its passagesfare alined and identical. The passages may beform'ed in variousways (for example see applicants Patent No. 2,390,913, issued December to the cylinders.

'When no supercharger is 11,1945, after the presentflapplication was filed).

'but in the example illustratedthe use of tubes is indicated:

eentrance to feach' passage is adjacent to the cylinder connection, so the eifectivelengths of the individual passages approximate twice the length of the manifold. This is sufficient to avail of inertia effects which improve the flow of air While the invention will be described as applied to an inlet manifold. because that is believed to be the field in which it has its, greatest utility. the construction can be used in any case where lon'g individual passages. all of approximately the. same length. are desired.

used, both ends of the manifold shell may be open to the atmosphere. When a supercharger is used it .is commonly connected with one end of the shell and the other end thereof is closed.- I

A preferredembodiment ofthe invention, as applied to a six cylinder in-line engine, will now be described by reference to the accompanying drawing.

In the drawing- Fig. 1 is an elevation 'of a manifold according to the invention, the mid-portion thereof being broken away to reduce the length of the figure, and portions being broken away at one cylinder connection.

s (on. res-s2) Fig. 2 is an elevation (partly sectioned) showing one or the tube loops, not in the twisted helicoid form to which itis formed.

Fig. 3 is a diagram in which one loop is shown in its twisted or helicoidal form in full lines. The outlines of the enclosing shell and the locations of the various cylinder connections are indicated in dotted lines.

Fig. 4 is a section on the line 4-4 of Fig. 1.

Fig. 5 is a section on the line 5-5 of Fig. 1.

Fig. 6 is a fragmentary section on the line i-t of Fig. 5. j

The manifold includes a shell 8 with flanged joints I, end cap 8, entrance flare 9 and inlet connection ii leading. from any source of air such as the atmosphere or a supercharger (not shown) In Fig. 1, connection ii is indicated by legend to be connected with a supercharger. When no The manifold has six elbows l2, welded to -it.

and these form the inlet connections to a six cylinder in-llne engine. In Fig. 1 only four of these are visible (two being in the portion broken away at the middle), but as indicated in Fig. 3

there isa connection for each of six cylinders and these connections preferably are uniformly spaced. 1 w

g The shell 8 is cylindrical, as shown. and nested around the internal periphery and slightly spaced apart are six tube loops I; (see Fig. 2). Each loop has a nipple it (which is welded to shell 6) and an entrance port Ii separated by a combined deflector. and partition it. Thus air entering at it flows the entire length of loop i No reachconnection it. Each loop may be regarded as comprising two longitudinal runs connected at the ends of the. runs by U-bends.

The loops l3 (1. e.) the longitudinal runs thereof) are twisted into helicoid form as indicated in Fig. 3. The pitch of the helix is such as to permit the connections ll to vbe alined andgether, and hence can be formed, assembled and welded without serious difliculty. For example the U-bends may be formed separately, and be welded to the runs after the latter are assembled in the middle portion of shell 6.. The flanged joints 1 permit the end portions of shell 6 to be placed last. 7

At first glance, Fig. might seem to indicate that the loops practically close the ends of shell 6. This is not true however, because the return bends are in difierent planes. Moreover, the inlet connections do not open all at the same time, so that the required rate of flow is not prohibitive.

The invention makes it possible to provide a unitary inlet or other manifold, little'longer than the engine and of practicable diameter, the mamfold having individual passages leading to the various cylinders and of uniform length at least twice the length of the engine. The efiect of such 1 an inlet manifold is to improve the delivery of air to all cylinders, by providing a supercharging tendency. This is of substantial benefit without a supercharger and materially improves the-performance of a supercharger when one is used.

Since all the individual passages are substantially the same in form and dimension, all cylinders are imilarly served. The inlets I5 all are fed from an axial passage large enough to ensure even flow.

The use of water cooling jackets in the shell is not illustrated, because usually not needed in an inlet manifold. Moreover, such an addition would involve only mechanical skill, considering the present state of the art.

Various modifications within the scope of the inventive concept are possible. For example, while I prefer to arrange the two runs of any single loop passage so that they are substantially diametrically opposite each other in shell 6 because such an arrangement aflords return bends of long radius, this condition is not strictly necessary. Other arrangements are possible, some of which would require modification'of the helical pitch. The invention is applicable to engines of various numbers of cylinders.

What is claimed is: y

1. In a manifold for multicylinder engines, the combination of an enclosing shell having a series of alined cylinder connections; and means forming a series of loop shaped passages, one for each connection, arranged side by side around the in- 4 terior of said shell, about a central axial space and extending substantially from end to end of said shell, said passages each havinga connection with a corresponding cylinder connection, an adjacent port communicating with said axial space and a partition interposed between the two whereby flow between said port and said connection passes through substantially the entire length of the corresponding loop shaped passage.

7 2. In a manifold for multicylinder engines, the combination of an enclosing shell having a series of alined cylinder connections; and means forming a series of loop shaped passages, one for each connection, arranged side by side around the interior of said shell, abouta central axial space and extending substantially from end to end of said shell, said passages each having a connection with a corresponding cylinder connection, an adjacent port communicating with said axial space and a partition interposed between the two whereby flow between said port and said connection passes through substantially the entire length of the corresponding loop shaped passage, said passages as a group being helically displaced.

3. The combination defined in claim 1 in which the passages' are formed by individual tubular loops nested' in the shell.

4. In a manifold for multicylinder engines, the

combination of an enclosing shell having a series of alined cylinder connections; and means forming a series of loop'shaped passages, one for each connection, arranged side by side around the interior of the shell about a central axialspac'e, said passage extending substantially from end to end of the shell, in two runs which are substantially diametrically opposed relatively to the shell and connected with each other at the ends of the shell, said passages having each a connection with a corresponding cylinder connection, an adjacent port communicating with said axial space and a partition interposed between the two, whereby flow between said port and said connection passes through substantially the entire length of the corresponding loop shaped passage, said passages as a group being helically displaced.

5. The combination defined in claim 4 inwhich the passages are formed by individual tubular loops nested in the shell, with nested cross-connecting U -bends between the two runs of the loop near the ends of the shell.

CHARLES G. BARRETT. "1

REFERENCES CITED a The following references are of record inithe 1,612,377 Jepson Dec. 28, 1926 

